function countDown(countdown){
	t_se += 1000;
	var leftTime = end.getTime()-star.getTime() - t_se;
	var leftSecond = parseInt(leftTime/1000);
	// 距离现在的天数
	var day = Math.floor(leftTime/(24*60*60*1000));
	var hour= Math.floor((leftSecond - day*24*60*60)/3600);
	var minu= Math.floor((leftSecond - day*24*60*60 - hour*3600)/60);
	var sec= Math.floor((leftSecond - day*24*60*60 - hour*3600)- minu*60);
	console.log(day+"tian "+hour+"xiaoshi "+minu+"fenzhong"+sec);
}
